#include <stdio.h>

void   print ( double x );
double square( double x );     // Try repeating the declaration... it's OK
double square( double x );


int main( int argc, char *argv[] )
{
   double a, b;

   a = 4.0;

   b = square( a );  // Call function square

   print( a );       // Call function print
   print( b );       // Call function print                  
}

void print ( double x )
{
   printf("Number = %lf\n", x );
}

double square( double x )                  
{
   double r;        // Define a local variable         

   r = x * x;       // Statement

   return ( r );    // Return statement
}